1. Field of the Invention
The present invention relates to processes for producing spreadable dairy products.
2. Description of the Prior Art
The methods of producing butter and butter/margarine blend products are quite varied with some being quite old. One method that is well known in the prior art, is simply taking cream and placing the cream in a churn and churning the cream until butter is formed. Another method is described in the Hobbs U.S. Pat. No. 263,042 issued on Aug. 22, 1882. The Hobbs Patent describes a process wherein a fraction of vegetable oil is subjected to pressure and temperature to make the vegetable oil compatible with an "animal oleo margarine." The "animal oleo margarine" and the vegetable oil are melted and mixed with cream before emulsionizing. The mixture is then churned to obtain the "artificial butter" of the Hodds Patent.
In both methods described above, churning is used to convert an oil-in-water emulsion to a water-in-oil emulsion. In an oil-in-water emulsion, such as dairy cream, the water phase is the continuous phase and the emulsion has properties similar to water. In a water-in-oil emulsion, such as butter, the oil is in the continuous phase and the emulsion exhibits properties similar to oil, such as being greasy.
Other patents disclose further refinements in the production of spreadable dairy products, especially patents directed to the production of butter/margarine blend products. The Lauferty U.S. Pat. Nos. 264,714 and 265,833 issued on Sept. 19, 1882 and Oct. 10, 1882, respectively, the Cochran U.S. Pat. No. 285,878 issued on Oct. 2, 1883, the Libreich U.S. Pat. No. 611,495 issued on Sept. 27, 1898, the Winship et al U.S. Pat. No. 1,028,804 issued on June 4, 1912, the Wall U.S. Pat. No. 1,386,475 issued on Aug. 2, 1921, the Hunziker U.S. Pat. No. 1,527,586 issued on Feb. 24, 1925, the Vahlteich U.S. Pat. No. 2,485,634 issued on Oct. 25, 1949, and the Johansson U.S. Pat. No. 4,209,546 issued on June 24, 1980, describe various processes wherein a cream and vegetable oil are mixed and then churned.
Still other processes described in other patents include homogenizing a milk/vegetable oil mixture by passing the mixture through a homogenizer or an emulsifying machine. In the Ashby U.S. Pat. No. 1,400,341 issued on Dec. 13, 1921, an 80% vegetable oil and 20% milk mixture is passed through an emulsifying machine prior to churning. In the Forman et al U.S. Pat. No. 4,177,293 issued on Dec. 4, 1979, a lowfat content butter spread is produced by starting with cream which can include a vegetable oil, innoculating the mixture and then homogenizing. After homogenization, fermentation is permitted and the mixture is homogenized a second time. The product is then directly packaged.
Still other patents describe processes for making a spreadable dairy product without using a churn. The patents include the Dubuisson U.S. Pat. No. 598,561 issued on Feb. 8, 1898, the Lillard U.S. Pat. No. 859,823 issued July 9, 1907, the Kronenberger U.S. Pat. No. 1,024,009 issued on Apr. 23, 1912, the Zeuthen et al U.S. Pat. No. 1,345,657 issued on July 6, 1920, the Karpinsky et al U.S. Pat. No. 1,644,254 issued on Oct. 4, 1927, the Feremutsch U.S. Pat. No. 2,051,797 issued on Aug. 18, 1936, the Shafer et al U.S. Pat. No. 2,745,750 issued on May 15, 1956, and the Schaap U.S. Pat. No. 3,386,835 issued on June 4, 1968.
Other patents describe various processes which use a "Votator" paddle-type device for cooling a dairy product to a more viscous form.
The Japikse U.S. Pat. No. 3,425,843, issued on Feb. 4, 1969, describes a process that produces an emulsion for use in a salad dressing. One of the steps in the process consists of rapidly chilling the emulsion within a "Votator".
The Ebskamp U.S. Pat. No. 4,217,372, issued on Aug. 12, 1980, describes a process for improving the structural properties of fats by cooling an aqueous margarine solution through a series of apparatus which have rotating shafts and paddles and cooling zones.
The Pichel U.S. Pat. No. 3,338,720, issued on Aug. 29, 1967, also uses a Votator for making a margarine product by first churning the margarine emulsion and then passing the emulsion through a "Votator" for crystallization.
In addition, several other patents describe processes for producing margarine wherein the margarine is passed initially through a "Votator" and then is homogenized. These patents include the Rourke et al U.S. Pat. No. 2,611,707 issued on Sept. 23, 1952, the Wilson et al U.S. Pat. No. 2,592,224 issued on Apr. 8, 1952, the McGowan et al U.S. Pat. No. 2,797,164 issued on June 25, 1957, and the Gander et al U.S. Pat. No. 3,488,199 issued Jan. 6, 1970.
There are also several continuous processes for producing butter which are of interest and not described in any of the previously-mentioned prior art patents.
One process is known as the "Gold'n Flow" continuous buttermaking system by the Cherry-Burrell Company. Briefly, the Gold'n Flow process starts with cream in a holding tank. From the holding tank, the cream is pumped through a filter to a destabilizing unit. The destabilizing unit whips and partially destabilizes the cream prior to entry into a separator. In the separator, the fat content of the cream is increased to 88% or higher with light and heavy skim milk being removed as a byproduct. After the separator, the cream which is now a fat concentrate is discharged into a second surge tank and into a three-stage vacuum-type pasteurizer. From the pasteurizer, the fat concentrate is pumped into a "composition control unit" wherein the fat concentrate is analyzed for further processing. After the composition control unit, the concentrate flows into a butter chiller which is similar to a "Vogt Freezer". From the chiller, the butter is discharged at a temperature of about 40.degree. F. and directly into a texturizer which allows time for the fat to crystallize and which further works the butter by forcing the butter through a perforated plate at its discharge end. When the butter leaves the texturizer, it is firm enough for printing and wrapping. The Cherry-Burrell process is also mentioned on page 587 of the "Fundamentals of Dairy Chemistry", by Webb, Johnson and Alford (3d ed.) 1980.
Another continuous process produces anhydrous milk fat, also called butter oil, which is approximately 99% butterfat. This continuous process is sold commercially by Carnation Company and briefly includes the following steps. First, the cream is concentrated from 40% to 80% fat content by first increasing the temperature of the fluid cream to 145.degree. F. and pushing the cream into a centrifugal separator wherein the cream is concentrated to a range of 78-80% fat. Second, the phase of the concentrated cream is reversed from fat in serum to serum in fat. The concentrated cream is pumped into a phase reverser, a machine similar to a homogenizer. By controlling the pressure, the phase reverser breaks the membrane of the fat globules, releasing the fat from its globular state, the processing pressure ranging generally from 1200 to 1400 pounds. The third step is to concentrate the fat concentrate to 98-99% fat. The fourth step includes processing the 98-99% fat content concentrate through a centrifugal oil polisher which further increases the fat concentrate to 99.5%.
Still another continuous process, commonly referred to as the "Creamery Package Process", is mentioned in the "Fundamentals of Dairy Chemistry", by Webb, Johnson and Alford, pp. 587-588 (3d ed.) 1980. The "Creamery Package Process" utilizes homogenization to destabilize reseparated cream to produce butter.
Another process which produces a butter/margarine blend product is the subject of an application entitled, "Process for Making Butter/Margarine Blend" having Ser. No. 339,378 which was filed on Jan. 15, 1982 and is assigned to the same assignee as the present invention. The process includes homogenizing a skim milk/vegetable oil mixture such that the globule size of the vegetable oil is reduced to a size range naturally found in cream. The homogenized skim milk/vegetable oil mixture is then mixed with cream having a 40% butterfat content and the oil/cream mixture is then churned in a conventional continuous butter churn. Although the immediately described process produces a satisfactory butter/margarine blend product, the churning byproduct, buttermilk, contains amounts of vegetable oil. Amounts of vegetable oil in the buttermilk limit the range of use of the buttermilk.